[llvm] 2461cdb - [CodeGen][SimplifyCFG] Teach DwarfEHPrepare to preserve DomTree

[Roman Lebedev via llvm-commits]

On Sat, Jan 2, 2021 at 1:54 PM Martin Storsjö <martin at martin.st> wrote:
>
> On Fri, 1 Jan 2021, Roman Lebedev via llvm-commits wrote:
>
> >
> > Author: Roman Lebedev
> > Date: 2021-01-02T01:01:19+03:00
> > New Revision: 2461cdb41724298591133c811df82b0064adfa6b
> >
> > URL: https://github.com/llvm/llvm-project/commit/2461cdb41724298591133c811df82b0064adfa6b
> > DIFF: https://github.com/llvm/llvm-project/commit/2461cdb41724298591133c811df82b0064adfa6b.diff
> >
> > LOG: [CodeGen][SimplifyCFG] Teach DwarfEHPrepare to preserve DomTree
>
> Hi,
Hi!

> This caused a notable compile time performance regression. With
> https://martin.st/temp/libyuv-preproc.cpp compiled with "clang -target
> x86_64-w64-mingw32 -w -c -O2", the compile time went from around 75
> seconds to 145 seconds, almost doubling it.
Yep, i can reproduce, will push the fix in a second.

It's a very stupid bug. I guess i was even warned about this problem
by my subconsciousness when writing commit message
for 4b80647367950ba3da6a08260487fd0dbc50a9c5.

> // Martin
Roman